Kurt Busch, no longer worrying about making NASCAR's Chase for the Nextel Cup championship, earned his series-leading fifth pole of the season Friday at California Speedway.

A 37th-place finish last Saturday at Bristol ended Busch's outside shot at making the 10-man Chase field in his first season with Penske Racing South. The 2004 Cup champion is now concerned with finishing this season strong and building momentum for 2007.

``Just to have the pressure of the Chase _ whether you're in or whether you're out _ gone, that makes things easier for us,'' Busch said moments after posting a lap of 184.540 m.p.h. in qualifying for the Sony HD 500.

``Now, we want to try some off-the-wall setups,'' he said. ``Until now, we've had to be pretty conservative and those setups were not good enough to get us in the Chase. Now we're free to try some different things that could really help us next year.''

Qualifying really hasn't been the problem for Busch this year, though.

``We're good on Friday,'' he said. ``We just need to get a little better on Sunday. ... We've been real solid with the power and setups underneath me. We need to make them last for more than a lap.''

Busch, who has seven career poles, also took the top qualifying spot here in February and finished 16th in the race.

Brian Vickers was the runner-up Friday at 184.049, followed by rookie Clint Bowyer at 183.505, Scott Riggs at 183.197 and rookie Martin Truex Jr. at 182.950.

Dale Earnhardt Jr., who was on top before Busch's run, wound up sixth, the fastest of the drivers battling for a spot in the Chase.

Series leader Jimmie Johnson and runner-up Matt Kenseth, who have sewn up spots in NASCAR's playoffs, qualified 16th and 11th, respectively.

Among the other Chase contenders, Jeff Burton was seventh, rookie Denny Hamlin eighth, Kasey Kahne _ 11th in the standings _ ninth, Kyle Busch 10th, Jeff Gordon 14th, Kevin Harvick 15th, defending champion Tony Stewart 22nd and Mark Martin _ 10th in the points _ was far off the pace in 38th.

``I just messed up my lap out there,'' said Martin, who has a 90-point lead over Kahne. ``These guys all ran faster, so I tried to run too fast. But we'll be all right in the race.''